


Undertale story ideas

by 13thcatofthegate



Category: Deltarune (Video Game), Undertale
Genre: AUs, Genderswap, Multi, Mythtale, Swapfell, Underfell, blaster born, gltchrelim, legondfell, underswap - Freeform
Language: English
Status: Completed
Published: 2019-02-24
Updated: 2019-02-24
Packaged: 2019-11-04 18:18:20
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 20
Words: 3,256
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17903144
Author URL: https://archiveofourown.org/users/13thcatofthegate/pseuds/13thcatofthegate
Summary: This is a collection of short story ideas that I've came up with. If there is a story you like let me know I just might add to it.





	1. Helping blood

**Summary for the Chapter:**

> Horrortale/genderswap

Helping Blood-  
Just a story idea- Horror/Genderswap  
Sandra had met Blood a few times and knew that the tale brothers had helped out Sugar with his teeth. Sandra always felt sad seeing that nasty hole in Bloods skull. So one day she offered to fix it for him, she’d do everything in her ability as a doctor to help. Blood agreed and it took a three hour long procedure to reconstruct his skull. He had to wear bandages around his head for a week after.  
“Okay Blood lets see if this looks better. Now the cracks are still going to be there but at least your skull won’t have a hole in it.” Sandra carefully unwrapped the bandages seeing that the bone graft had worked. Handing Blood a mirror he could see how it looked.  
“Wow, good job doc. What did you use to replace the missing bone?” Asked Sans.  
“Oh, that… I found a human that donated what I needed. Luckily he was a match for you Blood.” Both Sans looked at her shocked then Blood got a grin across his face. “Would that human be living at this very moment?”

“No, lets just say a poor soul took his own life and I made use of what he left behind.” 


	2. Sandra and the Ancient one

**Summary for the Chapter:**

> Genderswap/blaster born

Sandra and the Ancient one-  
Story idea-  
Sandra had finished taking a look at the ancient one finding that it’s more like her son than she thought.   
“Well now that that’s over with, tell me about yourself.”  
“… The young one… you call Jr. reminds me of one of my sons.” to Sandra’s surprise the voice was like a deep woman’s.   
“I was a breeder during the war… had seven pups… they all died in one way or another. Got hurt, put on the battlefield, survived.”


	3. Blaster born

**Summary for the Chapter:**

> blaster born

The blaster born-  
(story idea)  
Jr had been told that he was the first, and he saw it upon himself to keep track of any others. The blaster born, that’s what his mother called them. So far he has counted 4 of his kind including himself. His twin sons Romulus and Remus, and Demon were the other 3. Not to long ago Demon had given him the news that another was on the way. Demon had also asked that he be the new pup’s godfather.   
When his sister in-law Hecate gave birth Jr was there to be one of the first to see the baby. When Demon handed the bundle over to him Jr saw nothing out of the ordinary. The baby girl looked like a normal skeleton, that was until he saw her feet and noticed a tail.   
“So, what are you going to call her?” asked Demon.  
“…Autumn.”


	4. Seam and Jevil

**Summary for the Chapter:**

> Deltarune

Seam and Jevil-  
Story idea-  
Seam sat clutching his left eye as blood seeped through his fingers the pain almost unbearable. Jevil stood above him holding the freshly plucked eye in his claw chuckling as he looked it over.  
“I’ll take this as payment for our deal Seam. Your king shall rule until the heroes come to defeat them.”  
Seam winced in pain as the eye was turned into a black marble and placed into Jevil’s pocket.  
“And the rest of the deal?” Jevil grinned leaning down to look at Seams face.  
“Yes, I’m yours till you die, don’t disappoint me.”


	5. Dad meet Demon

**Summary for the Chapter:**

> Glitchrelim/underfell

Dad meet Demon-  
“Dad, I’d like you to meet Demon.”   
Edge looked over his shoulder at his daughter and the strange skeleton standing next to her.  
“… This is Demon?” Edge stood a few inches taller than Demon and made a very intimidating first impression.   
“So, my daughter seems to like you… What’s your Lv?” Demon had to get a bit of confidence back before answering. “6.”  
“What makes you think you’re good enough for my daughter?” Edge scowled crossing his arms.  
“Well, I have my own universe. A castle, gold, and a small army if needed.”


	6. Demon, Aurora and Pet.

**Summary for the Chapter:**

> Glitchrelim

Demon, Aurora and Pet-  
“Brother, have you talked with Pet much?” Demon looked up from his paperwork as his sister moved behind his desk.  
“I’ve talked to her.” Aurora scrunched her nose. “Not in that way, I mean really talk to her.”   
“… I’ve tried, she doesn’t talk to me.”   
“She talks to me, maybe you need to just be nicer to her.”  
“Tell me pet, why don’t you speak to my brother? Is it a human thing?” Aurora asked as Pet finished cleaning the ball room of the castle. She had just got all the dust swept up. “It’s not a human thing, well I guess it can be. You see Aurora I wasn’t born into a rich family… I had no family. The people who were taking care of me were very mean.”  
Aurora looked up at her confused. “But we’re your family.” Pet let out a small laugh getting down to her knees. “It was before I came here, before your brother took me in. You see they didn’t like kids and I was beaten when I talked or did something they didn’t like. I learned quick to keep my mouth shut and do as told. I don’t talk to your brother because he’s in charge, I don’t want to leave because I said something I shouldn’t.”  
“You know my brother won’t do something like that! You have to speak up or you’re never going to get out of the servants quarters.”


	7. Demon and his Pet.

**Summary for the Chapter:**

> Glitchrelim

Demon and his pet-  
Story idea-  
It was a dark night and the halls of the castle were quiet save for chirping of frogs and crickets outside in the garden. From the dark a small figure poked their head out of Tuffet’s room. With the speed of anyone scared of the dark they ran for Demons room. Their small feet making little pattering noises as their long night gown fluttered around them. Catching their breath they gripped the small blanket and something tucked under their arm.   
Demon was sleeping curled up in his king sized bed facing away from the door. He was deep in sleep until something woke him, startled he sat up seeing the small child on the bed next to him. “ Pet? What’s wrong, why are you not in bed?” Pet took what she was carrying from the bed holding it up for him to see. “A story, you want me to read you a story?” She nodded Demon was not in the mood to read being woken up so suddenly. “You’re not going to leave without me reading that are you?” Pet nodded again. Letting out a sigh he turned on the bedside lamp as pet sat next to him covering herself with the blanket she had brought with her. Taking the book Demon made sure they were both ready.   
“Yawn* Okay, once upon a time.”


	8. Pele

**Summary for the Chapter:**

> Mythtale

Pele-  
“So this is where you ran off to.” The monsters at the fort stood in shock as the front gate was left with a large burnt hole where the lava monster had walked through.   
“Pele, you fallowed me all the way here.” Sandra stayed back almost hiding behind Sans and the others. “Oh, you knew I’d catch up with you… now, are you coming back with me?” Sandra shook her head no.  
“Humph, always rebellious to the end… Well, maybe I should take your sister back with me. You know full well she belongs in my kingdom more than this one.”  
Papi stood scared as the lava monster stepped closer to her. The heat was almost unbearable as a molten hand reached for her. There was a flash of blue and black as someone stepped between them. “No! Papi belongs here!!” Pele pulled back amazed that a fairy would do something like this.   
“You’re not taking her anywhere!” Blue growled. “I’ve burned thousands of bugs like you, looks like one more won’t matter.” Pele gathered some molten rock before cucking it at the fairy. Blue couldn’t move in time closing his eyes ready to take the impact. In a split second he was shielded by a large wing and crushed against Papi. “Are you hurt?” She asked as the heat started to dissipate. Blue had to blink himself back to reality hearing the molten stone crack and pop.   
Getting out from under her wing he saw where the attack had hit. To his surprise it had done no damage to her at all. The lava beaded off of her feathers like water and the small pieces that remained were cooling into glass.


	9. MT Sandra x Flowey

**Summary for the Chapter:**

> Mythtale

MT Sandra x Flowey?  
Sandra noticed something moving in the flower bed once the yellow flower she had avoided for the last 13years appeared her additude changed.   
“What are you doing here Flowey?” The Flower got a grin across it’s face. “Howdy, Sandra. How are you doing?”  
Sandra was tempted to rip him out of the dirt with the way he seemed to forget about what had happened between them. “Go away, I told you never to get near me ever again.”   
“I’m here about Tickseed…” Sandra looked shocked as Flowey’s grin faded.   
“…I never should of pollenated with you.”


	10. Love hotel

**Summary for the Chapter:**

> Twin Papi idea.

Love hotel-  
Papyrus walked along with the twins as they admired the venders of the crowded street. There were many fun and interesting things that both humans and monsters were selling.   
“Wow, look at this!” “That’s so cute!” the twins chattered as they looked things over. Papyrus looked at other items waiting for them pick something out. Their day had started going to a carnival and ended with them in this night market. Papyrus liked hanging out with twins. They could keep up with his high energy and made things twice as fun. They didn't pick anything out and quickly they headed farther down the street. The stores were giving away food stores and hotels.   
“Hey look at this.” Yellow Papi said pointing to a sign that said love hotel on it.   
“What’s a love hotel?” Red Papi asked.


	11. Edge and Sandra

**Summary for the Chapter:**

> Underfell/genderswap

Spycymayo-  
Sandra was walking out of Reds room after he had fallen asleep. In the living room she could see Hecate and Holly sleeping on the floor worn out from their sleepover party. She was about to head back to bed when a door creaking caught her attention. Looking towards Edge’s room it was open a crack. She thought she could see a glowing red eye watching her. Glaring back at it for a moment she begun to walk towards the room. There was a sudden shuffle as she stood almost in front of it.   
Pushing the door open a bit she could see Edge in bed but she could tell he was only pretending to be asleep. Chuckling a bit she closed the door and walked back to Reds room.   
The next day Sandra brought up the events of last night with Red. “Sandra said you were watching her last night.”  
‘I-I heard her in the hall, I just wanted to see who it was.” Edge tried to not make eye contact letting Red know there was something more going on then just checking. “You know I don’t mind if you like her Boss, just don’t be such a creep about it.”  
Edge finally looked at him, “You don’t mind?”


	12. Flowey x Papi

**Summary for the Chapter:**

> genderswap/undertale

Flowey x Papi-  
Just an Idea. What if Papi and Flowey ended up being together?    
Papi walked outside dressed in her gardening outfit ready to take care of the plants. Her garden didn’t have much a large carpet of yellow buttercups and daylilies. As she was getting rid of the weeds a vine wrapped around her hand.   
“Hey sweetheart, what cha’ doing?” Looking over Flowey had appeared in the buttercups. Giving him a smile she leaned over and kissed him. “Just cleaning up, I’ve been slacking off, sorry about that.” 


	13. Grillby and Sythe

**Summary for the Chapter:**

> Undertale

Grillby and Sythe-  
It was closing time and Grillby was taking out the trash when he stopped in his tracks. Sitting right next to the outside trash cans was a cat. Not just any cat a skeleton cat with green eyes. It looked up at him waiting for the bag to be thrown out. Once he did it climbed onto the cans looking for something to eat.  
“Hello, I haven’t seen you around.” Grillby reached out his hand but didn’t try to pet it. For a moment the cat looked him over before sniffing at him. There was a tense moment not sure if it was going to scratch him. But when the cat rubbed it’s skull into his fingers he let out a sigh and scratched it’s jaw.   
“Well, your hungry right?” The cat looked up at him. “I could make you a good meal, there are some leftovers from today.” The cat let out a excited meow as it allowed Grillby to pick them up. “How good are you at catching rats?”

  
Just a story idea for some of the things Sythe dose as odd jobs for other monsters. Hunting rats at Grillby’s is one of them, in return she gets fed.

Grillby liked having Sythe around the bar. She’d lounge around the windows and sometimes the bar stools. Every once in a while she’d catch a rat with the death squeak making who ever was at the bar go quiet.   
One night Sans was at the bar having not seen the cat yet. He was getting ready to order when she jumped onto the stool next to him. “You’re in her seat.” said Grillby. Sans shrugged, “Sorry cat but it’s my seat now.” Sythe looked up at him giving him a growl and tail twitch. Once Sans had gotten his food he noticed a little paw clawing at his plate stealing a fry. He was about to swat at the cat when it jumped under the bar. “Dumb cat.” he said looking for a dazed cat that had ran into the hardwood bar. To his surprise the cat had disappeared.  
“What the hell?” Grillby laughed as Sans sat back up into his seat. On the nearest window the cat was enjoying her stolen fry. 


	14. Good boys

**Summary for the Chapter:**

> undertale/underswap

Papyrus x Blueberry-  
Papyrus had invited Blueberry over for a movie night. Sans had gone out with Red and knew they could be gone for a night or two. Everything was going as well as it could, watching a movie, eating popcorn and sharing stories.   
Towards the end of the night Papyrus was starting to feel funny. Every time Blue brushed against him his body would tingle. Also it seemed as if the room was getting hotter.  
Blue was enjoying himself hanging out with Papyrus when he noticed his friend acting a bit strange. There was an odd whimper and sigh every now and then. 


	15. Glitch, Nera and Echo

**Summary for the Chapter:**

> glitchrelim

Glitch/Nera/Echo-  
Glitch went to see her sister after finding out something while recoding a monster. “Nera! I got it!! I know how to fix Echo!!”  
Nera jumps up from the chair she was reading a book in making it thud against the floor. “What? What are you talking about?”  
“I can fix Echo’s code so he can see!” Nera looked at her in shock then in a look of worry. “You want to fix Echo’s code so he can see?”  
“Yes, I know I can do it.”  
“…No, you’ve only been messing with codes for only a short while. What if you can’t, what if you end up making him worse?” Nera looked her sister dead in the eyes looking for the reassurance that if she tried it would work. But it wasn’t there, Glitch was only giving the hope of something beyond her powers.    
“Echo is fine the way he is, you shouldn’t try to fix him if you’re not sure you can do it right Glitch.”


	16. Underhut

**Summary for the Chapter:**

> Underhut

Underhut-  
windigo is a mythical cannibal monster or evil spirit native to the northern forests of the Atlantic Coast and Great Lakes Region of both the United States and Canada. The wendigo may appear as a monster with some characteristics of a human or a spirit who has possessed a human being and made them become monstrous. It is historically associated with cannibalism, murder, insatiable greed, and the cultural taboos against such behaviours.  
Shaman (Steph) has become distant from the others even Archer was turned away. There was a moment of panic one day when one of the rabbit monsters was found dusted. The amount of blood in the area told them that the monster died violently. Soon after a new monster was spotted stocking a group of children. For a moment Archer thought they were talking about Shaman with what they described. But the size of the monster was wrong, it was way too tall and it’s limbs were way too long.  
Worried, Archer tried once again to talk to Shaman only to find her missing.  
Underhut is by- serenecatbird


	17. Jr.

**Summary for the Chapter:**

> Blaster born

Jr.-  
Jr. has gone missing and Rune thinks that the humans had something to do with it. There had been rumors in the underground that they were looking for monsters to use as playthings. Stories of monsters thrown into battle arenas or forced into slavery have them worried.   
Rune takes off looking for Jr. leaving their sons in the care of their grandmother Sandra. Of course the twins want to find their father as well fallowing Rune out of the underground and into the dangerous world of the humans.   
(This takes place in Genderswap AU.)


	18. black rose

**Summary for the Chapter:**

> Swapfell/genderswap

Black rose-  
Sandra was looking for Red or Sans getting more agitated when she couldn’t find them. She knew Blue was out training with Alpys and she didn’t want to pull him away from something that important to him. But she had already put off taking care of her heat for too long. Just then Raspberry knocked on her door asking if Slim was there with her sister.  
“Raz, now’s not the time for you to be here.” Sandra tried to close the door when he stuck his foot inside stopping her from doing so.   
“You do know I can smell that right? Your heat must be in full swing… I’d help you with that, but , you said that you don’t enjoy my company.”   
Sandra leaned against the door her body shaking. “…I know what you want Raz… I’ll give it to you if you help me out.”


	19. Echo

**Summary for the Chapter:**

> Glitchrelim

Echo-  
“How in the hell did you end up with two mates?” Echo turned his head a bit as he laughed under his breath at the other monster.  
“Lucky I guess.” The other monster growled not liking his answer.  
“Like hell you’re lucky, you’re blind and not that powerful. You must of tricked those girls! You wouldn’t be able to protect both of em’ so how’s about I take one off your hands?” Echo looked strait at the other monster making it jump.   
“I didn’t trick them and they need no protection from me. You’re more than welcome to try and take one, but I’m sure no one will miss you once you turn to dust.”


	20. Legondfell

**Summary for the Chapter:**

> Legondfell

Legondfell-  
“Sigh, today was not a good day.” Pepper sat at his desk covered in pages of spells he had been working on. Most of them were waiting to be tested to see if they should be added to the battle mage spell book. But he was so tired and wanting to crawl into bed. At least Viper would be there waiting for him so she could wrap herself around his body in that all to familar hug of hers. He shivered as images of that pink scaled tail rubbing against his bones reminded him of their many nights together.   
“… The rest of this can wait.” Clicking his fingers as he got up the candles in the room went out. “Vipers waiting." 


End file.
